(a) Field of the Invention
The present invention relates to, for example, an organic electroluminescence display device. More particularly, the present invention relates to an organic electroluminescence display device in which uniformity of color coordinates is obtained by controlling the thickness of a SiNx layer under an organic light-emitting element.
(b) Description of Related Art
An organic electroluminescence display device is a light-emitting display device. The mechanism that causes light to emit is the dropping of excitons (created by combination of injected electrons and holes) from an excited state to a ground state. The electrons and holes are typically injected into a light-emitting layer by an electron injection cathode and a hole injection anode.
An organic electroluminescence display device does not require a separate light source. Thus, it may be thinner and lighter than a liquid crystal display.
The organic electroluminescence display device is divided into a passive matrix type organic electroluminescence display device and an active matrix type organic electroluminescence display device depending on its driving method.
Because of high power consumption and scaling difficulties, the passive matrix type organic electroluminescence display device is typically used only for small displays. Active matrix type organic electroluminescence display devices are typically used for displays with a large area.
SiNx is typically used as an insulating layer in an active matrix type organic electroluminescence display device. SiNx can help to provide protection as a passivation layer formed after a thin film transistor (which can be used for driving the organic light-emitting element).
However, the SiNx layer has low light transmittance. It also affects the uniformity of color (spectrum waveform) of light emitted from the organic electroluminescence display device, because there can be large thickness deviations in the layer. The usual reason for these thickness variations is that the layer is generally formed by chemical vapor deposition.